Tool Having A Mounting Opening For Positive Connection To Different Drive Shafts

ABSTRACT

A tool is disclosed having a mounting opening for positive connection to a drive shaft that can be driven oscillatingly, the mounting opening comprising a plurality of outwardly extending projections each having an outer convex section that ends on both sides in concave lateral flanks, with neighboring lateral flanks joining each other on their way toward the center axis of the mounting opening to form a common bulge, concave on the outside, the shape of the outwardly extending projections, of the lateral flanks and of the bulges being such that there can be effected, optionally, either a positive connection to a first raised securing section of a first drive shaft, having a plurality of outwardly extending convex raised portions each having a rounded tip and rounded concave lateral flanks, or, optionally, a positive connection to a second securing section of a second drive shaft, having a plurality of raised positive-connection elements arranged in regular intervals on a circular line.

BACKGROUND OF THE INVENTION

The present invention relates to a tool having a mounting opening for positive connection to a first drive shaft that can be driven oscillatingly and which comprises a first raised securing section having a plurality of convex raised portions each extending toward the outside and provided with a rounded tip and rounded convex lateral flanks.

The invention further relates to a tool having a mounting opening for positive connection to a second drive shaft that can be driven oscillatingly and which comprises a second securing section having a plurality of raised positive-connection elements of substantially trapezoidal shape arranged in regular intervals along a circular line.

A tool of the first-mentioned kind is known from U.S. Pat. No. 6,945,862.

According to this document, which is incorporated herein in full by reference, a drive shaft of an oscillating drive, that can be driven oscillatingly, is provided with a raised securing section on which are provided a total of four raised portions, each extending from a circular line to the outside and provided with a rounded tip and with rounded convex lateral flanks.

A tool having an mounting opening with recesses of matching shape can be mounted on such a securing section in form-locking fashion.

From US 2008/0190259 A1, which is also incorporated herein in full by reference, there is further known a tool having an mounting opening for positive connection to a second drive shaft that can be driven oscillatingly, the second oscillatingly driven drive shaft comprising a second raised securing section provided with a total of twelve raised positive-connection elements of substantially trapezoidal shape that are arranged along a circular line at regular intervals. A matching tool that is to be mounted on that securing section is provided with corresponding recesses adapted to that shape. In that case, too, the angle of the tool relative to the drive shaft can be adjusted.

The tools that are to be connected to the different drive shafts are provided with corresponding mounting openings matched to the shapes of the different securing sections of the drive shafts.

It is, therefore, necessary that different tools be held on stock for the different drive shafts.

SUMMARY OF THE INVENTION

It is a first object of the present invention to disclose a tool having a mounting opening suited for positive connection to the different kinds of drive shafts mentioned above.

It is a second object of the invention to disclose a tool having a mounting opening that allows an angular adjustment of the tool relative to a drive shaft on which it is attached.

It is a third object of the invention to disclose a tool having a mounting opening suitable for attachment on different oscillatingly driven drive shafts, thereby allowing larger volumes in the production of tools and reducing inventory needs.

These and other objects of the invention are achieved by a tool having a mounting opening for positive connection to a drive shaft that can be driven oscillatingly, the mounting opening comprising a plurality of outwardly extending projections each having an outer convex section that ends on both sides in concave lateral flanks, with neighboring lateral flanks joining each other on their way toward the mounting opening to form a common bulge or apex, concave on the outside, the form of the outwardly extending projections, of the lateral flanks and of the bulges being such that there can be effected, optionally, either a positive connection to a first raised securing section of a first drive shaft, having a plurality of outwardly extending convex raised portions each having a rounded tip and rounded concave lateral flanks, or a positive connection to a second securing section of a second drive shaft having a plurality of raised positive-connection elements that are arranged in regular intervals on a circular line.

A tool according to the invention allows a positive connection to be effected, by mounting it on the securing section of the respective shaft, to both a first drive shaft having a plurality of outwardly projecting concave raised portions each having a rounded tip and rounded concave lateral flanks, and to a second drive shaft having a second securing section which latter comprises a plurality of raised positive-connection elements of trapezoidal shape arranged in regular intervals along a circular line.

In this way, it is possible to use a single tool for positive connection to a first drive shaft and also for positive connection to a second drive shaft.

One thereby obtains clearly greater quantities for the respective tools so that as a result corresponding cost savings can be achieved and it is no longer necessary to produce and distribute different tools serving the same purpose for the different drive shafts.

One achieves in this way considerable savings in terms of costs and logistics.

According to a further embodiment of the invention, the outer ends of the projections and the inner ends of the bulges, respectively, are arranged along circles concentric to the center axis. Also preferably, the raised positive-connection elements that are arranged on a circular line have a rectangular or substantially trapezoidal shape.

The design of the mounting opening is preferably symmetrical relative to the center axis.

This allows a positive connection to be achieved with both known mounting systems.

According to a further embodiment of the invention, the number of projections of the mounting opening is an integral multiple of the number of the convex raised portions of the first securing section and of the number of the trapezoidal positive-connection elements of the second securing section.

This allows the tool to be adjusted in angular position relative to the drive shaft. When the number of projections of the mounting opening is a multiple of the number of the convex raised portions of the first securing section or of the number of trapezoidal positive-connection elements of the second securing section, then the tool can be secured on the drive shaft at even smaller angular increments than would be defined by the number of convex raised portions of the first securing section or the number of trapezoidal positive-connection elements of the second securing section.

In that connection, the number of projections of the mounting opening may, for example, be twelve and the number of convex raised portions or of trapezoidal positive-connection elements may be three, four, six of twelve.

According to a further embodiment of the invention, the mounting opening is configured as a stamped opening.

This permits the mounting opening to be produced easily and at low cost.

According to a preferred embodiment of the invention, the tool may, for example, be a grinding tool, a cutting tool or a sawing tool.

It is understood that the features of the invention mentioned above and those yet to be explained below can be used not only in the respective combination indicated, but also in other combinations or in isolation, without leaving the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparent from the description that follows of certain preferred embodiments, with reference to the drawing. In the drawing

FIG. 1 shows a perspective view of an exemplary design of a tool provided with a mounting opening according to the invention:

FIG. 2 shows a perspective view of a first drive shaft of an oscillating drive with a raised securing section, designed for positive connection to a mounting opening of the tool according to FIG. 1;

FIG. 3 shows a perspective view of a second drive shaft of a second oscillating drive with a securing section for connection to the mounting opening of the tool according to FIG. 1, likewise in form-locking fashion; and

FIG. 4 shows a schematic side view of an oscillating drive with a drive shaft according to FIG. 2, and a tool according to FIG. 1 mounted on it.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a perspective view of an exemplary embodiment of a tool according to the invention, designated generally by reference numeral 10. In the illustrated case, the tool 10 comprises a triangular working surface 12 with rounded tips and convex outer edges extending between the tips. The working surface 12 may be coated with a sanding material directly, or may be designed for having a sanding disk of corresponding shape and size secured to it. A mounting opening 16 is accommodated in an offset portion 14 in the middle of the surface, in recessed relation to the working surface 12.

The mounting opening 16 comprises a total of twelve outwardly extending projections 20 each provided with an outer convex section 22 that ends on both sides in a respective concave lateral flank 24. On their way to the center axis 18 of the mounting opening 16, neighboring lateral flanges 24 join each other to form a common bulge 26 of concave shape on the outside. The outer ends of the convex sections 22 and the inner ends of the concave bulges 26, respectively, are arranged on circles concentric to the center axis 18 of the mounting opening 16. Generally, the mounting opening 16 is symmetrical relative to the center axis 18. Thus the projections 20 are arranged at equal angular intervals between each other.

FIG. 2 shows a matching first drive shaft 30 of an oscillating drive (FIG. 4) with a raised first securing section 38 according to U.S. Pat. No. 6,945,862. The drive shaft 30, that can be driven oscillatingly about its longitudinal axis 32 in the direction indicated by arrow 34, comprises a flange 36 that serves as an abutment for the tool 10. A mounting opening 16 of the tool 10 can be mounted on the securing section 38 so that a positive connection is effected.

As a safety measure, a securing screw 72 is used, for example, that can be screwed into a corresponding threaded bore 46 in the drive shaft 30—see FIG. 4—in a manner such that the securing screw 72 is countersunk within the offset portion 14.

As known from U.S. Pat. No. 6,945,862, the securing section 38 has a total of four convex raised portions 40 which extend from a circle toward the outside and which have a rounded tip 42 and rounded concave lateral flanks 44.

The shape of the mounting opening 16 of the tool 10 is matched to the shape of the securing section 38 of the first drive shaft 30 so that a positive connection to the drive shaft is guaranteed. As the mounting opening 16 has a total of 12 projections 20, while the securing section 38 of the first drive shaft 4 has four raised portions 40, it is now possible to secure the tool on the drive shaft 36 in twelve angular positions offset one from the other by 30°.

FIG. 3 shows a second drive shaft of a second oscillating drive, indicated generally by reference numeral 50. That drive shaft, too, can be driven by its associated oscillating drive oscillatingly about its longitudinal axis 52, as indicated by the double arrow 54. Again, there is provided a flange 56 on which a mounting opening 58 is formed. The mounting opening comprises in this case a total of twelve positive-connection elements 60 which are arranged along a circular line concentric to the center axis 52 and which have a trapezoidal shape, for example, and are raised toward the top (in principle, they may of course also have a rectangular or circular cross-section or any other cross-sectional shape).

Now, the form of the mounting opening 16 of the tool 10 is selected so that the tool 10 can be mounted on the first drive shaft 30 or, alternatively, also on the second drive shaft 50, being in each case positively held by its mounting opening 16. In this case again, a threaded bore 46 serves to receive a screw that is intended to secure the tool 10 on the drive shaft 50.

Details of the shape and design of the securing section 58 of the second drive shaft 50 can be taken from US 2008/0190259 A1, which is fully incorporated herein by reference.

The oscillating drive 70 according to FIG. 4 is an oscillating drive of a design known as such, which causes its drive shaft 30 to perform rapid oscillating movements about the longitudinal axis 32 of the drive shaft 30, at a frequency of, for example, 5000 to 30000 oscillations per minute and with a small oscillating angle of, for example, 0.5 to 5 degrees.

Such an oscillating drive may be equipped with a drive shaft 30 according to FIG. 2 or with a drive shaft 50 according to FIG. 3.

A tool having a mounting opening 16 according to the invention can be mounted optionally on different oscillating drives that are equipped with the first drive shaft 30 or with the second drive shaft 50. A positive connection is guaranteed in both cases. 

1. A tool having a mounting opening configured for positive connection to a drive shaft that can be driven oscillatingly about its longitudinal axis, the mounting opening comprising a plurality of outwardly extending projections each having an outer convex section ending on both sides in concave lateral flanks, with neighboring lateral flanks joining each other on their way toward the center axis of the mounting opening to form a common bulge, concave on the outside; wherein said projections have outer ends and said bulges have inner ends, both said outer ends and said inner ends being arranged along circles concentric to said center axis; and wherein said outwardly extending projections, said lateral flanks and said bulges define a shape of the mounting opening being matched to a first raised securing section of a first drive shaft and to a second raised securing section of a second drive shaft, so as to allow, optionally, either a positive connection to said first raised securing section of said first drive shaft, having a plurality of outwardly extending convex raised portions each having a rounded tip and rounded concave lateral flanks, or, optionally, a positive connection to said second raised securing section of said second drive shaft, having a plurality of raised positive-connection elements of rectangular or substantially trapezoidal shape, arranged in regular intervals on a circular line.
 2. A tool having a mounting opening configured for positive connection to a drive shaft that can be driven oscillatingly about its longitudinal axis, the mounting opening comprising a plurality of outwardly extending projections each having an outer convex section ending on both sides in concave lateral flanks, with neighboring lateral flanks joining each other on their way toward the center axis of the mounting opening to form a common bulge, concave on the outside; wherein said outwardly extending projections, said lateral flanks and said bulges define a shape of the mounting opening so as to allow, optionally, either a positive connection to a first raised securing section of a first drive shaft, having a plurality of outwardly extending convex raised portions each having a rounded tip and rounded concave lateral flanks, or, optionally, a positive connection to a second raised securing section of a second drive shaft, having a plurality of raised positive-connection elements arranged in regular intervals on a circular line.
 3. The tool of claim 2, wherein said mounting opening has a shape so as to allow a positive connection to said second raised securing section of said second drive shaft, having a plurality of raised positive-connection elements of rectangular or substantially trapezoidal shape arranged on a circular line.
 4. The tool of claim 1, wherein said projections have outer ends and said bulges have inner ends, both said outer ends and said inner ends being arranged along circles concentric to said center axis.
 5. The tool of claim 1, wherein said mounting opening has a total number N of projections, wherein said first raised securing section comprises n, convex raised portions, wherein said second raised securing section comprises a total of n₂ positive-connection elements, and wherein said total number N is an integral multiple of n, convex raised portions and of n₂ positive-connection elements.
 6. The tool of claim 2, wherein said mounting opening has a total number N of projections, wherein first raised securing section comprises n, convex raised portions, wherein said second raised securing section comprises a total of n₂ positive-connection elements, and wherein said total number N is an integral multiple of n, convex raised portions and of n₂ positive-connection elements.
 7. The tool of claim 5, wherein said total number N is 12, said number n, of said convex raised portions is 3, 4, 6 or 12, and said number n₂ of said positive-connection elements is 3, 4, 6 or
 12. 8. The tool of claim 6, wherein said total number N is 12, said number n, of said convex raised portions is 3, 4, 6 or 12, and said number n₂ of said positive-connection elements is 3, 4, 6 or
 12. 9. The tool of claim 1, wherein said mounting opening is configured as a stamped opening.
 10. The tool of claim 2, wherein said mounting opening is configured as a stamped opening.
 11. The tool of claim 1, which is configured as a grinding tool.
 12. The tool of claim 1, which is configured as a scraping tool.
 13. The tool of claim 1, which is configured as a sawing tool.
 14. The tool of claim 2, which is configured as a grinding tool.
 15. The tool of claim 2, which is configured as a scraping tool.
 16. The tool of claim 2, which is configured as a sawing tool. 